1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_S390_STACKTRACE_H 3 #define _ASM_S390_STACKTRACE_H 4 5 #include <linux/stacktrace.h> 6 #include <linux/uaccess.h> 7 #include <linux/ptrace.h> 8 9 struct stack_frame_user { 10 unsigned long back_chain; 11 unsigned long empty1[5]; 12 unsigned long gprs[10]; 13 unsigned long empty2[4]; 14 }; 15 16 struct stack_frame_vdso_wrapper { 17 struct stack_frame_user sf; 18 unsigned long return_address; 19 }; 20 21 struct perf_callchain_entry_ctx; 22 23 void arch_stack_walk_user_common(stack_trace_consume_fn consume_entry, void *cookie, 24 struct perf_callchain_entry_ctx *entry, 25 const struct pt_regs *regs, bool perf); 26 27 enum stack_type { 28 STACK_TYPE_UNKNOWN, 29 STACK_TYPE_TASK, 30 STACK_TYPE_IRQ, 31 STACK_TYPE_NODAT, 32 STACK_TYPE_RESTART, 33 STACK_TYPE_MCCK, 34 }; 35 36 struct stack_info { 37 enum stack_type type; 38 unsigned long begin, end; 39 }; 40 41 const char *stack_type_name(enum stack_type type); 42 int get_stack_info(unsigned long sp, struct task_struct *task, 43 struct stack_info *info, unsigned long *visit_mask); 44 45 static inline bool on_stack(struct stack_info *info, 46 unsigned long addr, size_t len) 47 { 48 if (info->type == STACK_TYPE_UNKNOWN) 49 return false; 50 if (addr + len < addr) 51 return false; 52 return addr >= info->begin && addr + len <= info->end; 53 } 54 55 /* 56 * Stack layout of a C stack frame. 57 * Kernel uses the packed stack layout (-mpacked-stack). 58 */ 59 struct stack_frame { 60 union { 61 unsigned long empty[9]; 62 struct { 63 unsigned long sie_control_block; 64 unsigned long sie_savearea; 65 unsigned long sie_reason; 66 unsigned long sie_flags; 67 unsigned long sie_control_block_phys; 68 unsigned long sie_guest_asce; 69 }; 70 }; 71 unsigned long gprs[10]; 72 unsigned long back_chain; 73 }; 74 75 /* 76 * Unlike current_stack_pointer which simply contains the current value of %r15 77 * current_frame_address() returns function stack frame address, which matches 78 * %r15 upon function invocation. It may differ from %r15 later if function 79 * allocates stack for local variables or new stack frame to call other 80 * functions. 81 */ 82 #define current_frame_address() \ 83 ((unsigned long)__builtin_frame_address(0) - \ 84 offsetof(struct stack_frame, back_chain)) 85 86 static __always_inline unsigned long get_stack_pointer(struct task_struct *task, 87 struct pt_regs *regs) 88 { 89 if (regs) 90 return (unsigned long)kernel_stack_pointer(regs); 91 if (task == current) 92 return current_frame_address(); 93 return (unsigned long)task->thread.ksp; 94 } 95 96 /* 97 * To keep this simple mark register 2-6 as being changed (volatile) 98 * by the called function, even though register 6 is saved/nonvolatile. 99 */ 100 #define CALL_FMT_0 "=&d" (r2) 101 #define CALL_FMT_1 "+&d" (r2) 102 #define CALL_FMT_2 CALL_FMT_1, "+&d" (r3) 103 #define CALL_FMT_3 CALL_FMT_2, "+&d" (r4) 104 #define CALL_FMT_4 CALL_FMT_3, "+&d" (r5) 105 #define CALL_FMT_5 CALL_FMT_4, "+&d" (r6) 106 107 #define CALL_CLOBBER_5 "0", "1", "14", "cc", "memory" 108 #define CALL_CLOBBER_4 CALL_CLOBBER_5 109 #define CALL_CLOBBER_3 CALL_CLOBBER_4, "5" 110 #define CALL_CLOBBER_2 CALL_CLOBBER_3, "4" 111 #define CALL_CLOBBER_1 CALL_CLOBBER_2, "3" 112 #define CALL_CLOBBER_0 CALL_CLOBBER_1 113 114 #define CALL_LARGS_0(...) \ 115 long dummy = 0 116 #define CALL_LARGS_1(t1, a1) \ 117 long arg1 = (long)(t1)(a1) 118 #define CALL_LARGS_2(t1, a1, t2, a2) \ 119 CALL_LARGS_1(t1, a1); \ 120 long arg2 = (long)(t2)(a2) 121 #define CALL_LARGS_3(t1, a1, t2, a2, t3, a3) \ 122 CALL_LARGS_2(t1, a1, t2, a2); \ 123 long arg3 = (long)(t3)(a3) 124 #define CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4) \ 125 CALL_LARGS_3(t1, a1, t2, a2, t3, a3); \ 126 long arg4 = (long)(t4)(a4) 127 #define CALL_LARGS_5(t1, a1, t2, a2, t3, a3, t4, a4, t5, a5) \ 128 CALL_LARGS_4(t1, a1, t2, a2, t3, a3, t4, a4); \ 129 long arg5 = (long)(t5)(a5) 130 131 #define CALL_REGS_0 \ 132 register long r2 asm("2") = dummy 133 #define CALL_REGS_1 \ 134 register long r2 asm("2") = arg1 135 #define CALL_REGS_2 \ 136 CALL_REGS_1; \ 137 register long r3 asm("3") = arg2 138 #define CALL_REGS_3 \ 139 CALL_REGS_2; \ 140 register long r4 asm("4") = arg3 141 #define CALL_REGS_4 \ 142 CALL_REGS_3; \ 143 register long r5 asm("5") = arg4 144 #define CALL_REGS_5 \ 145 CALL_REGS_4; \ 146 register long r6 asm("6") = arg5 147 148 #define CALL_TYPECHECK_0(...) 149 #define CALL_TYPECHECK_1(t, a, ...) \ 150 typecheck(t, a) 151 #define CALL_TYPECHECK_2(t, a, ...) \ 152 CALL_TYPECHECK_1(__VA_ARGS__); \ 153 typecheck(t, a) 154 #define CALL_TYPECHECK_3(t, a, ...) \ 155 CALL_TYPECHECK_2(__VA_ARGS__); \ 156 typecheck(t, a) 157 #define CALL_TYPECHECK_4(t, a, ...) \ 158 CALL_TYPECHECK_3(__VA_ARGS__); \ 159 typecheck(t, a) 160 #define CALL_TYPECHECK_5(t, a, ...) \ 161 CALL_TYPECHECK_4(__VA_ARGS__); \ 162 typecheck(t, a) 163 164 #define CALL_PARM_0(...) void 165 #define CALL_PARM_1(t, a, ...) t 166 #define CALL_PARM_2(t, a, ...) t, CALL_PARM_1(__VA_ARGS__) 167 #define CALL_PARM_3(t, a, ...) t, CALL_PARM_2(__VA_ARGS__) 168 #define CALL_PARM_4(t, a, ...) t, CALL_PARM_3(__VA_ARGS__) 169 #define CALL_PARM_5(t, a, ...) t, CALL_PARM_4(__VA_ARGS__) 170 #define CALL_PARM_6(t, a, ...) t, CALL_PARM_5(__VA_ARGS__) 171 172 /* 173 * Use call_on_stack() to call a function switching to a specified 174 * stack. Proper sign and zero extension of function arguments is 175 * done. Usage: 176 * 177 * rc = call_on_stack(nr, stack, rettype, fn, t1, a1, t2, a2, ...) 178 * 179 * - nr specifies the number of function arguments of fn. 180 * - stack specifies the stack to be used. 181 * - fn is the function to be called. 182 * - rettype is the return type of fn. 183 * - t1, a1, ... are pairs, where t1 must match the type of the first 184 * argument of fn, t2 the second, etc. a1 is the corresponding 185 * first function argument (not name), etc. 186 */ 187 #define call_on_stack(nr, stack, rettype, fn, ...) \ 188 ({ \ 189 rettype (*__fn)(CALL_PARM_##nr(__VA_ARGS__)) = fn; \ 190 unsigned long frame = current_frame_address(); \ 191 unsigned long __stack = stack; \ 192 unsigned long prev; \ 193 CALL_LARGS_##nr(__VA_ARGS__); \ 194 CALL_REGS_##nr; \ 195 \ 196 CALL_TYPECHECK_##nr(__VA_ARGS__); \ 197 asm volatile( \ 198 " lgr %[_prev],15\n" \ 199 " lg 15,%[_stack]\n" \ 200 " stg %[_frame],%[_bc](15)\n" \ 201 " brasl 14,%[_fn]\n" \ 202 " lgr 15,%[_prev]\n" \ 203 : [_prev] "=&d" (prev), CALL_FMT_##nr \ 204 : [_stack] "R" (__stack), \ 205 [_bc] "i" (offsetof(struct stack_frame, back_chain)), \ 206 [_frame] "d" (frame), \ 207 [_fn] "X" (__fn) : CALL_CLOBBER_##nr); \ 208 (rettype)r2; \ 209 }) 210 211 /* 212 * Use call_nodat() to call a function with DAT disabled. 213 * Proper sign and zero extension of function arguments is done. 214 * Usage: 215 * 216 * rc = call_nodat(nr, rettype, fn, t1, a1, t2, a2, ...) 217 * 218 * - nr specifies the number of function arguments of fn. 219 * - fn is the function to be called, where fn is a physical address. 220 * - rettype is the return type of fn. 221 * - t1, a1, ... are pairs, where t1 must match the type of the first 222 * argument of fn, t2 the second, etc. a1 is the corresponding 223 * first function argument (not name), etc. 224 * 225 * fn() is called with standard C function call ABI, with the exception 226 * that no useful stackframe or stackpointer is passed via register 15. 227 * Therefore the called function must not use r15 to access the stack. 228 */ 229 #define call_nodat(nr, rettype, fn, ...) \ 230 ({ \ 231 rettype (*__fn)(CALL_PARM_##nr(__VA_ARGS__)) = (fn); \ 232 /* aligned since psw_leave must not cross page boundary */ \ 233 psw_t __aligned(16) psw_leave; \ 234 psw_t psw_enter; \ 235 CALL_LARGS_##nr(__VA_ARGS__); \ 236 CALL_REGS_##nr; \ 237 \ 238 CALL_TYPECHECK_##nr(__VA_ARGS__); \ 239 psw_enter.mask = PSW_KERNEL_BITS & ~PSW_MASK_DAT; \ 240 psw_enter.addr = (unsigned long)__fn; \ 241 asm volatile( \ 242 " epsw 0,1\n" \ 243 " risbg 1,0,0,31,32\n" \ 244 " larl 7,1f\n" \ 245 " stg 1,%[psw_leave]\n" \ 246 " stg 7,8+%[psw_leave]\n" \ 247 " la 7,%[psw_leave]\n" \ 248 " lra 7,0(7)\n" \ 249 " larl 1,0f\n" \ 250 " lra 14,0(1)\n" \ 251 " lpswe %[psw_enter]\n" \ 252 "0: lpswe 0(7)\n" \ 253 "1:\n" \ 254 : CALL_FMT_##nr, [psw_leave] "=Q" (psw_leave) \ 255 : [psw_enter] "Q" (psw_enter) \ 256 : "7", CALL_CLOBBER_##nr); \ 257 (rettype)r2; \ 258 }) 259 260 #endif /* _ASM_S390_STACKTRACE_H */ 261